Refactor processing algorithm classes

Removes redundancies in processing algorithm classes by
creating the ORSBaseProcessingAlgorithm class.

Moved to base class:
- basic attributes and functions
- provider and output parameter
- algorithm and ors_client initialization

Other notable changes:
- moved from class to instance attribute approach
- clean algorithm class naming
- build_default_parameters moved to directions_core
- easier access to input values in processAlgorithm()
- rename of help files for dynamic loading
- moved from lookupField() to indexOf()

closes #133

ORStools/common/directions_core.py

@@ -34,6 +34,7 @@
                        QgsFeature,
                        QgsFields,
                        QgsField)
+from typing import List
 
 from PyQt5.QtCore import QVariant
 
@@ -191,3 +192,34 @@ def get_output_features_optimization(response, profile, from_value=None):
                         ])
 
     return feat
+
+
+def build_default_parameters(preference: str, point_list: List[QgsPointXY] = None, coordinates: list = None) -> dict:
+    """
+    Build default parameters for directions endpoint. Either uses a list of QgsPointXY to create the coordinates
+    passed in point_list or an existing coordinate list within the coordinates parameter.
+    TODO no optimal solution, maybe let get_request_point_features() return QgsPointXY as well to only use point_list
+
+    :param preference: routing preference, shortest/fastest/recommended
+    :type preference: str
+
+    :param point_list:
+    :type point_list: list of QgsPointXY
+
+    :param coordinates:
+    :type coordinates: list
+
+    :returns: parameters for directions endpoint
+    :rtype: dict
+    """
+    coords = coordinates if coordinates else [[round(point.x(), 6), round(point.y(), 6)] for point in point_list]
+    params = {
+        'coordinates': coords,
+        'preference': preference,
+        'geometry': 'true',
+        'instructions': 'false',
+        'elevation': True,
+        'id': None
+    }
+
+    return params

ORStools/common/isochrones_core.py

@@ -155,11 +155,11 @@ def stylePoly(self, layer):
         """
 
         if self.dimension == 'time':
-            legend_suffix = ' mins'
+            legend_suffix = ' min'
         else:
             legend_suffix = ' m'
 
-        field = layer.fields().lookupField(self.field_dimension_name)
+        field = layer.fields().indexOf(self.field_dimension_name)
         unique_values = sorted(layer.uniqueValues(field))
 
         colors = {0: QColor('#2b83ba'),

ORStools/proc/__init__.py

@@ -26,8 +26,3 @@
  *                                                                         *
  ***************************************************************************/
 """
-import os.path
-
-from ORStools import BASE_DIR
-
-HELP_DIR = os.path.join(BASE_DIR, 'help')

ORStools/proc/base_processing_algorithm.py

@@ -0,0 +1,148 @@
+# -*- coding: utf-8 -*-
+"""
+/***************************************************************************
+ ORStools
+                                 A QGIS plugin
+ QGIS client to query openrouteservice
+                              -------------------
+        begin                : 2017-02-01
+        git sha              : $Format:%H$
+        copyright            : (C) 2021 by HeiGIT gGmbH
+        email                : support@openrouteservice.heigit.org
+ ***************************************************************************/
+
+ This plugin provides access to openrouteservice API functionalities
+ (https://openrouteservice.org), developed and
+ maintained by the openrouteservice team of HeiGIT gGmbH, Germany. By using
+ this plugin you agree to the ORS terms of service
+ (https://openrouteservice.org/terms-of-service/).
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+"""
+from qgis.core import (QgsProcessingAlgorithm,
+                       QgsProcessingParameterEnum,
+                       QgsProcessingParameterFeatureSink,
+                       QgsProcessingFeedback
+                       )
+from typing import Any
+
+from PyQt5.QtGui import QIcon
+
+from ORStools import RESOURCE_PREFIX, __help__
+from ORStools.utils import configmanager
+from ..common import client
+from ..utils.processing import read_help_file
+
+
+# noinspection PyPep8Naming
+class ORSBaseProcessingAlgorithm(QgsProcessingAlgorithm):
+    """Base algorithm class for ORS algorithms"""
+
+    def __init__(self):
+        """
+        Default attributes used in all child classes
+        """
+        super().__init__()
+        self.ALGO_NAME = ''
+        self.GROUP = ''
+        self.IN_PROVIDER = "INPUT_PROVIDER"
+        self.OUT = 'OUTPUT'
+        self.PARAMETERS = None
+
+    def createInstance(self) -> Any:
+        """
+        Returns instance of any child class
+        """
+        return self.__class__()
+
+    def group(self) -> str:
+        """
+        Returns group name (Directions, Isochrones, Matrix) defined in child class
+        """
+        return self.GROUP
+
+    def groupId(self) -> str:
+        return self.GROUP.lower()
+
+    def name(self) -> str:
+        """
+        Returns algorithm name defined in child class
+        """
+        return self.ALGO_NAME
+
+    def shortHelpString(self):
+        """
+        Displays the sidebar help in the algorithm window
+        """
+        return read_help_file(file_name=f'{self.ALGO_NAME}.help')
+
+    @staticmethod
+    def helpUrl():
+        """
+        Will be connected to the Help button in the Algorithm window
+        """
+        return __help__
+
+    def displayName(self) -> str:
+        """
+        Algorithm name shown in QGIS toolbox
+        :return:
+        """
+        return self.ALGO_NAME.capitalize().replace('_', ' ')
+
+    def icon(self) -> QIcon:
+        """
+        Icon used for algorithm in QGIS toolbox
+        """
+        return QIcon(RESOURCE_PREFIX + f'icon_{self.groupId()}.png')
+
+    def provider_parameter(self) -> QgsProcessingParameterEnum:
+        """
+        Parameter definition for provider, used in all child classes
+        """
+        providers = [provider['name'] for provider in configmanager.read_config()['providers']]
+        return QgsProcessingParameterEnum(
+            self.IN_PROVIDER,
+            "Provider",
+            providers,
+            defaultValue=providers[0]
+        )
+
+    def output_parameter(self) -> QgsProcessingParameterFeatureSink:
+        """
+        Parameter definition for output, used in all child classes
+        """
+        return QgsProcessingParameterFeatureSink(
+            name=self.OUT,
+            description=self.GROUP,
+        )
+
+    @staticmethod
+    def _get_ors_client_from_provider(provider: str, feedback: QgsProcessingFeedback) -> client.Client:
+        """
+        Connects client to provider and returns a client instance for requests to the ors API
+        """
+        providers = configmanager.read_config()['providers']
+        ors_provider = providers[provider]
+        ors_client = client.Client(ors_provider)
+        ors_client.overQueryLimit.connect(lambda: feedback.reportError("OverQueryLimit: Retrying..."))
+        return ors_client
+
+    # noinspection PyUnusedLocal
+    def initAlgorithm(self, configuration):
+        """
+        Combines default and algorithm parameters and adds them in order to the
+        algorithm dialog window.
+        """
+        parameters = [self.provider_parameter()] + self.PARAMETERS + [self.output_parameter()]
+        for param in parameters:
+            self.addParameter(
+                param
+            )